1. Field of the Invention
The present invention relates to a scroll compressor for supplying lubricant oil to the engaging portion between a fixed scroll and a swinging scroll and compressing refrigerant through the engagement between the fixed scroll and the swinging scroll.
2. Description of the Related Art
There is known a scroll compressor equipped with a compression mechanism comprising a fixed scroll and a swinging scroll that have spiral wraps engaged with each other in a hermetically sealed casing. In this scroll compressor, the compression mechanism is driven by a driving motor so that the swinging scroll makes circular motion relatively to the fixed scroll without rotating to compress refrigerant (see JP-A-2004-60532, for example).
In this type of scroll compressor, low-pressure refrigerant sucked from a suction pipe is compressed by the compression mechanism, and compressed high-pressure refrigerant is discharged from a discharge pipe provided to the casing to the outside of the casing. Furthermore, lubricant oil is supplied to each sliding portion of the compression mechanism and the engaging portion between the fixed scroll and the swinging scroll. The lubricant oil to be supplied is stocked in an oil reservoir provided at the lower portion of the casing, and surplus lubricant oil in the compression mechanism is returned to the oil reservoir by its own weight.
There is a case in this type of scroll compressor that lubricant oil is atomized in the casing due to rotation of a rotating body such as a driving shaft of the driving motor or the like. The atomized lubricant oil is mixed with high-pressure gas refrigerant to form mixed gas. The lubricant oil cannot be well separated from the mixed gas, and there may occur such a state that a large amount of atomized lubricant oil exists in the casing. Under the state that the mixed gas of a large amount of atomized lubricant oil and high-pressure refrigerant exists, a large amount of atomized lubricant oil may discharged from the discharge pipe to the outside of the casing together with the high-pressure refrigerant.